follow ft86club on our blog, twitter or facebook.
FT86CLUB
Ft86Club
Speed By Design
Register Garage Members List Calendar Search Today's Posts Mark Forums Read

Go Back   Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB > Technical Topics > Engine, Exhaust, Transmission

Engine, Exhaust, Transmission Discuss the FR-S | 86 | BRZ engine, exhaust and drivetrain.


User Tag List

Reply
 
Thread Tools Search this Thread
Old 07-29-2023, 04:42 PM   #1
blsfrs
Senior Member
 
blsfrs's Avatar
 
Join Date: Dec 2018
Drives: 2013 frs base
Location: central Virginia
Posts: 1,004
Thanks: 1,454
Thanked 764 Times in 410 Posts
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Should an oil cooler cause oil pressure to drop?

For the past few weeks, I've been studying oil coolers and sandwich plates.

A thermostatic sandwich plate is a "2 channel" system. When the engine is cold the oil flows through channel 1, bypassing the cooler. At 180*F or 82C* (whichever comes first) channel 2 opens to the cooler. Channel 1 is still open.

So, the amount of flow through the cooler is irrelevant. Even if the cooler only flowed 1/2 pint per fortnight, channel 1 is still open so oil pressure shouldn't drop.

What am I missing?
blsfrs is offline   Reply With Quote
Old 07-29-2023, 05:10 PM   #2
Ashikabi
Senior Member
 
Ashikabi's Avatar
 
Join Date: Aug 2014
Drives: 2013 FR-S
Location: Northwest Iowa
Posts: 7,353
Thanks: 454
Thanked 4,542 Times in 2,947 Posts
Mentioned: 59 Post(s)
Tagged: 5 Thread(s)
Channel 1 shouldn't really be open at temp. Pressure drop is caused by obstruction through the sandwich and heat exchanger. Unless I'm mistaken somehow

Sent from my KB2007 using Tapatalk
Ashikabi is offline   Reply With Quote
The Following 2 Users Say Thank You to Ashikabi For This Useful Post:
blsfrs (07-29-2023), Ultramaroon (07-29-2023)
Old 07-29-2023, 05:52 PM   #3
Ultramaroon
Database Error
 
Ultramaroon's Avatar
 
Join Date: Sep 2014
Drives: a 13 e8h frs
Location: vantucky, wa
Posts: 31,606
Thanks: 51,584
Thanked 36,156 Times in 18,746 Posts
Mentioned: 1103 Post(s)
Tagged: 9 Thread(s)
Pressure drop is real. Accelerating mass around sharp corners, turbulent flow, blah blah... all is work resulting in head loss.
__________________
Ultramaroon is offline   Reply With Quote
The Following User Says Thank You to Ultramaroon For This Useful Post:
blsfrs (07-29-2023)
Old 07-29-2023, 08:05 PM   #4
Jianlun
Senior Member
 
Join Date: Sep 2018
Drives: GR86 RC
Location: Singapore
Posts: 203
Thanks: 80
Thanked 178 Times in 91 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by blsfrs View Post
For the past few weeks, I've been studying oil coolers and sandwich plates.

A thermostatic sandwich plate is a "2 channel" system. When the engine is cold the oil flows through channel 1, bypassing the cooler. At 180*F or 82C* (whichever comes first) channel 2 opens to the cooler. Channel 1 is still open.

So, the amount of flow through the cooler is irrelevant. Even if the cooler only flowed 1/2 pint per fortnight, channel 1 is still open so oil pressure shouldn't drop.

What am I missing?

Mocal http://www.mocal.co.uk/products-oilcoolers.html gives the pressure drop thru their various cores. But the engine will not feel this pressure drop most of the time since the oil pump is a positive displacement pump (will pump a fixed vol of oil vs engine rpm, ie higher rpm = more flow). So even if there is huge restriction at the oil cooler, it will try to maintain the flow and we end up with higher pressure after the pump before the oil cooler. Also, the pressure relief at the oil gallery is triggered for a large proportion of the rev range.

Unless the pump starts cavitating. A theory that needs to be tested.
Attached Images
 
Jianlun is offline   Reply With Quote
The Following User Says Thank You to Jianlun For This Useful Post:
blsfrs (07-30-2023)
Old 07-30-2023, 01:43 PM   #5
blsfrs
Senior Member
 
blsfrs's Avatar
 
Join Date: Dec 2018
Drives: 2013 frs base
Location: central Virginia
Posts: 1,004
Thanks: 1,454
Thanked 764 Times in 410 Posts
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
My question mainly revolves around what is happening at the sandwich plate. I see where the oil flow is open to the cooler at 180* but I don't see where that cuts off flow to "channel 1".

My choice of oil cooler was dictated by shortest and greatest number of tubes. The Sebrab Series 1, 34 row seemed to be the best compromise.
blsfrs is offline   Reply With Quote
Old 07-30-2023, 04:05 PM   #6
Grady
Senior Member
 
Grady's Avatar
 
Join Date: Jun 2017
Drives: BRZ Yellow, 2019 Ranger, 2011 Evora
Location: Dallas
Posts: 1,654
Thanks: 348
Thanked 1,451 Times in 755 Posts
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
Garage
A sandwich plate with a Vernatherm works different than you described. When cold the Vernatherm is short allowing oil to bypass the cooler. As the oil get hot it expands and shuts off the bypass and forcing all the oil to go through the cooler. Or some ratio between the two.
Grady is offline   Reply With Quote
The Following User Says Thank You to Grady For This Useful Post:
blsfrs (07-30-2023)
Old 07-30-2023, 10:28 PM   #7
blsfrs
Senior Member
 
blsfrs's Avatar
 
Join Date: Dec 2018
Drives: 2013 frs base
Location: central Virginia
Posts: 1,004
Thanks: 1,454
Thanked 764 Times in 410 Posts
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
You guys are correct. I found this video. For me, it helped clarify what the dang thing does.

blsfrs is offline   Reply With Quote
The Following User Says Thank You to blsfrs For This Useful Post:
Wally86 (07-31-2023)
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Oil temps/pressure after installing blitz oil cooler Mortsgreb Scion FR-S / Toyota 86 GT86 General Forum 4 08-24-2021 12:55 PM
Fuel Pressure Drop on my LS BRZ Shahano Engine Swaps 6 04-28-2021 05:57 PM
Temperature drop, tire pressure check! radroach Wheels | Tires | Spacers | Hub -- Sponsored by The Tire Rack 26 11-07-2016 09:43 PM
FS: Maximal Oil Cooler & Oil Pressure Gauge Tt3Sheppard Engine, Exhaust, Bolt-Ons 11 07-20-2016 03:48 PM
aftermarket oil cooler, pressure issues? BRZPDX Mechanical Maintenance (Oil, Fluids, Break-In, Servicing) 0 05-05-2014 11:36 AM


All times are GMT -4. The time now is 02:30 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2023, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2023 DragonByte Technologies Ltd.

Garage vBulletin Plugins by Drive Thru Online, Inc.